WASHINGTON (CNN) - In a wide-ranging interview set to air Sunday on CNN's State of the Union, one of President Barack Obama's most prominent Republican supporters says he is 'concerned' about the new president's ambitious agenda and the high price tags accompanying many of Obama's initiatives.

"I'm a little concerned," former Secretary of State Colin Powell says. "I'm concerned at the number of programs that are being presented, the bills associated with these programs and the additional government that will be needed to execute them."

Powell also seems to sound a note of warning to the young president.

"I think one of the cautions that has to be given to the president - and I've talked to some of his people about this - is that you can't have so many things on the table that you can't absorb it all. And we can't pay for it all."

Even as he raises concerns about the new Democratic president's agenda, Powell also seems to back away from some of his own conservative views.

"I don't like slogans anymore like 'limited government.' That's not the right answer. The right answer is, give me a government that works."

"The people want their problems solved," Powell also says in the interview. "And very often, it's government that has to do that. So let's have good government, effective government, whether you call it limited or not."

Despite his concerns, Powell also tells CNN Chief National Correspondent John King that he has a "very good" relationship with president.

"I have met with him not too long ago. I don't insert myself. But we stay in touch," the former Bush aide says of Obama.